1. Field of the Invention
The aim of this invention is a mechanism for the quick hooking and unhooking of a handle, used particularly for fly screens and fly screen assemblies made with this system.
The invention has particular, but not necessarily exclusive, application in the fixture accessories sector, such as fly screens, roller blinds and sun blinds.
2. Description of Related Art
Fly screens are divided into two categories. The first type is made to measure, manufactured according to the dimensions required for a given client, delivered to the said client and installed by a specialized installation technician. The other type is sold in kit form, and is the type that is most widely available on the market.
The latter type of fly screen is reasonably efficient and economic and is the type at which this invention is mainly aimed. Large quantities of components have to be fabricated and transported by the manufacturing companies, especially when dealing with overseas markets. The xe2x80x9cdo-it-yourselfxe2x80x9d concept is widely used and offers a product that satisfies most normal requirements, although it is not up to the standards of the made-to-measure type.
Both of the examples mentioned have certain components in common, such as the casing, which is generally made from extruded aluminum bar. It is used to contain the rewind mechanism for the fly screen, roller blind or sun blind, and the manual version has a corresponding loaded return spring. The ends of the casing are sealed by special plates or headers, which are supplied in two different versions, a fixed type or together with counter-plates or caps that can be regulated.
There are obviously a number of variations, although they are very similar to the systems described, and are just as common in fly screens as in roller blinds and sun blinds. One of these variations is a lower quality fly screen without the aforementioned return spring inside its mechanism. They differ from the first type in that they are manually operated both for unwinding and rewinding the fly screen. In this case, there is a closed-loop chain that hooks around a cog fixed on the relative rewind roll contained inside a casing for unwinding and rewinding the fly screen, roller blind or sun blind in a controlled manner.
These solutions foresee the fabrication of structures, for example fly screens, which are made up as follows:
a casing that is closed at the ends by corresponding headers;
a rewind roll contained inside the said casing, supported at both ends, that is fixed to the ends of the casing;
a helicoidal torsion spring positioned co-axially, that works in conjunction with the said rewind roll;
a rod positioned co-axially to the said helicoidal spring;
a piece of material or cloth, either net type or for shading purposes, joined at one end to the rewind roll, and at the other end to a handle;
and, two runners in which the two ends of the said handle and the edges of the said material or cloth slide.
Especially with the type that has the rewind roll controlled by the closed-loop chain mechanism, certain drawbacks have been encountered. They are due to the fact that the material or cloth is only held tight by the handle which is weighted. As a result, this type of structure has no means that acts upon the handle to counteract pressure exerted on the surface of the material or cloth. In fact, if the material or cloth is subjected to pressure on the surface, due to winds or a part of the body accidentally pushing against it, it is deformed according to the amount of pressure exerted, with the handle that is lifted proportionally to the said deformation of the material or cloth. This deformation, which is usually unstable, produces a phenomenon that is known as xe2x80x9csail effectxe2x80x9d and which is the main cause of the aforementioned drawbacks.
Firstly, the efficiency of the material or cloth may be compromised because, especially with the cheaper fly screens, the lateral edges tend to come out of the runners to leave openings through which insects or light may pass.
Secondly, because of the continuous effect of the wind which blows in various directions, the fly screen may be noisy, an effect that is increased by the sudden rubbing of the metallic components, due to the back and forth movement or the lateral play of the handle inside its relative runners.
To overcome these and other drawbacks, some consumers choose fly screens with two battens that slide horizontally rather than vertically. In this case, the material or cloth is wound by pulling the handle in one direction, and fixing it in position when it reaches its limit with vertically mobile fasteners, the ends of which go inside corresponding seats, usually positioned on the vertical runner. Since this type of fly screen has two battens, both purchase price and installation costs are higher. This is because two casings are usually required, each one positioned along the two sides in order to fit out the two spaces. A large part of the cost, according to the individual supplier, depends on the type of structure used which, operating in a different direction compared with traditional methods, requires complex manufacturing operations.
A fly screen known as Genius was recently put on the market, which was designed to overcome the aforementioned problems. It is particularly used for horizontal fly screens, with the movement of the rewind roll imposed by manual traction of a closed-loop chain. This type of fly screen structure, used for doors with a large inter-axis, is made up basically of:
a casing containing a rewind roll which is pre-charged by means of at least one torsion spring;
a screen fastened at one end to the rewind roll, with a handle at the other end;
runners in which the ends of the handle slide;
and, a handle, the ends of which have holding means on the lower side that fit inside the runners.
The user, when unwinding the screen, pulls the closed-loop chain in one direction to carry out the lowering of the screen, until its respective handle reaches the limit at the base of the opening in question. When this position has been reached, in order to fasten the handle and, therefore, the screen in a stretched position, the user carries out a further pull so that the handle, made out of a rectangular tubular profile, rotates and inclines slightly on one side. In this position, pieces that protrude from the two ends of the handle intercept dedicated seats formed on the lower side of the runners, forcing the pieces to take up a certain position. At this point, the user releases the closed-loop chain so that the screen, which is under tension, pulls the handle upwards to force it from a slightly inclined position into a vertical position, forcing the pieces into corresponding recesses with stop points.
In order to release the handle and rewind the screen, the structure has a type of pedal along the handle. The purpose of this pedal, which is located in a central position, is to co-operate with the action applied to the closed-loop chain when it is pushed by the user. In particular, the user has to apply a slight pull downward on the chain with one hand in order to move the screen, while pressing the pedal with a foot. The pressure applied in this way on the pedal obliges the handle to rotate on one side, releasing it from its holding point and, since it is now free, may be rewound due to elastic pull.
The drawbacks regard the complicated manoeuvre that the user has to carry out to release the handle so that the screen can be rewound, especially with fittings with a large inter-axis, for example the type with a double batten.
This manoeuvre requires co-ordination and simultaneous use of a hand and a foot, which not everybody is able to do. The manoeuvre requires the lifting of a leg, which is only possible if the person is not disabled and the distance is short. When the fitting is larger, on the other hand, the user has to almost be a contortionist, and it is certainly not possible for everybody to carry out this kind of manoeuvre, since it is difficult to reach the pedal with a foot, located at the centre of the handle.
The difficulty is increased if we consider that the manoeuvre has to be perfectly synchronised, and if it is not carried out correctly it is impossible to release the screen.
Secondly, and certainly not to be overlooked, regards the appearance of the system. With the system described above, in order to release the screen efficiently, there has to be a pedal, which is visible and may be an obstacle.
In view of the drawbacks mentioned above, alternative solutions are obviously required and the aim of the invention described herein is to overcome the aforementioned drawbacks.
This and other aims are achieved through the use of this invention according to the characteristics in the attached claims, solving the problems described by means of a mechanism for quick the hooking and unhooking of a handle, used particularly for fly screens and fly screen assemblies with a chain-operated movement, and that includes:
a casing containing a rewind roll that is pre-charged by means of at least one torsion spring;
a screen fastened at one end to the rewind roll, with a handle at the other end;
runners, in which the ends of the handle slide;
a handle with a tubular profile, with a hooking means on at least one end that operates in conjunction with a reciprocal holding means, located at the lower end of the corresponding runner. In the said holding means there is a block, which is fastened to the lower end of one of the runners. The said block is open on one side and has two surfaces that face each other that act as a guide with an entrance, an exit and an intermediate rest position. The said guide is hooked by a hooking means located at the end of the handle, and includes a guide piece, which longitudinally guides a mobile carriage. The said carriage has a protruding pin on at least one side that fits into at least one of the two guide-tracks in the block.
In this way, through the creative contribution of the system, which leads to an immediate technical progress, various advantages are achieved.
The first and, without a doubt, the most important advantage is that the hooking and releasing operations of the handle, while keeping the screen tight, are easier and more efficient. In order to unwind the screen, the user has to simply operate with the chain as with traditional systems to lower the handle down in the fitting in question, until a light resistance is felt. Upon continuing the operation, a mechanical xe2x80x9cclickxe2x80x9d is heard which means that the handle is now in place and the protective effect desired is guaranteed.
To rewind the screen, the user has to simply apply a further, light pull on the chain so as to unhook the handle, and control the movement of the chain during the rewinding of the screen, which is caused by the rewind spring that was put into tension during the lowering operation of the screen. No other part of the body is required, therefore, apart from the hands, an operation that is simple and that can be carried out by anybody, including old and most disabled people.
A second advantage is that the said mechanism is extremely efficient for all types of fly screens and rewind screens in general, whatever the size of the fitting to be fitted out. This leads to a rationalisation of components kept in stock by the manufacturers and suppliers, leading to a reduction in overall costs.
A further advantage is that the pieces that protrude from the handle are eliminated which, apart from increasing the cost of the component, meant that it was anti-aesthetic and formed an obstacle.
These and other advantages will be shown in the following detailed description and drawings of at least one preferred application of the system, which is to be considered merely an illustration and not a limitation.